"Single Fold Shutters" are for narrow "off center" glass on doors and "Multi Fold" are for doors with wider "centered" glass and also for SideLights

We have a video for every Shelter Shutter type and door type. We make Single Fold and Multi Fold Shelter Shutters. The only significant difference in door types would be if your door has raised molding or not. If your door does NOT have raised molding, you do not need spacers. If your door DOES have raised molding, you need spacers. Spacers come in pairs, one set is included with stock size shutters which will accomidate a door glass molding thickness of up to 1/8" thick. Extra spacers can be ordered for thicker moldings. Each set of spacers add 1/8". When you order custom shutters, the correct number of spacers will already be applied to the back of the shutter.